Heating means



Oct. 21, 1941. E. N. CALHOUN HEATING MEANS Filed June 6, 1940 lNvzNToR.ERN E51 N CALHOSLN ATTOQN Ers Patented Oct. 21, 1941 UNITED STATESPATENT OFFICE HEATING MEANS Ernest N. Calhoun, Pittsburgh, Pa., assignorto Edwin L. Wiegand, Pittsburgh, Pa.

Application June 6, 1940, Serial No. 339,119

9 Claims.

This invention relates to heatingmeans, more particularly to electricalheating means adapted generally for use with appliances which are to beelectrically heated, illustrative examples of which are ranges orstoves, hot plates, and the like, The principal object of this inventionis to provide new and improved heating means of the character described.

In the drawing accompanying this specification, and forming a part ofthis application, I have shown an embodiment which my invention mayassume, and in this drawing:

Figure 1 is a vertical sectional view of the embodiment of the inventionherein illustrated, the line'of section being generally shown by thesection line l-I in Figure 2, a

Figure 2 is a bottom plan view of the embodiment, parts being brokenaway to more clearly show the construction,

Figure 3 is a fragmentary separated perspective view of certain parts ofthe embodiment, and Figure 4 is a bottom plan view ofthe heating unit.

The embodiment of the invention herein shown is particularly adapted foruse as a range unit, and as shown in Figure 1, comprises a support,which inthe particular embodiment is in the form of a disk-like metallicplate i0, preferably formed by a casting operation, and constitutingpart of the heating unit. The top side, referring to the position ofparts in Figure 1, is preferably Electrical resistor means, andheat-conducting electric-insulating means are disposed in the groovesformed in the lower side surface of the plate l0. As herein illustrated,a single length of electrical resistance wire of the helically woundtype, either round in transverse section, as shown,

case, the refractory material is compacted in the grooves H and i2 insuch manner that the resistors and 2| are embedded therein, and are thusheld spaced from those surfaces defining flat and provides a heatingsurface on which arti-.

cles, such as pots, pans, kettles, or the like, are supported. The lowerside of the plate In is formed with channel means, as by grooves II andI2, which are here formed as spirals and are intercalated with respectto each other, as best seen in Figure 4.

The marginal edge of the plate I0 is formed with annular downwardlyextending peripheral flange means 13, and extending radially from theflange means l3 are a plurality of projectionsl4, here shown to be threein number, these projections being engageable within correspondingapertures l5 formed in a rim 16 of an adapter adjacent surfaces of theadapter ring I! and the' stove portion I 9., so that direct contactbetween the heating surface and the article to be heated is providedfor.

therespective groove, as best seen in Figure 1. Each of the resistors 20and 2| has a pair of connection leads 22 and 23 respectively, extendingoutwardly from the insulating material, as best seen in Figures 2 and 4.

A preferred method of properly positioning the resistors and therefractory material in the grooves of the plate comprises disposing theplate l0 groove side up on a suitable support, and loosely filling thegrooves H and I2 with'the refractory material, such material preferablybeing mixed with a certain amount of bonding clay, and moistened so thatit maybe worked somewhat like founders clay. The excess material fromthe upper side of the plate l0 (remembering providing a suitable diehaving projections shaped to closely flt the grooves H and I2, suchprojections carrying the resistors 20 and 2|, the latter and plate areseparated, the resistors are properly held positioned in the refractorymaterial in respective grooves. The grooves may then again be filledwith loose refractory material, and the excess material wiped from theplate, as before, and a die, somewhat like the die before described, butwithout resistors, is brought together with the plate It, to compact therefractory material. The heating unit may then be dried or baked, ifdesired.

' The lower side surface of the plate Iii is formed with laterallyextending centrally disposed circular flange means 25, circumscribing anopening 25 extending through the upper side of the plate I0, and at suchupper side the opening is formed with an enlargement 26, forming ashoulder El. The marginal surface defining the opening 25 has suchcontour as to provide an annular lip 28 so constructed that the shoulder2? forms the bottom of an annular recess, as best seen in Figure l. Theterminating margin 29 of the flange means 2 3 is formed withspaced-apart recesses or notches .30, here shown to be two in number anddiametrically opposed.

Reflector means 3| is provided for assembly with the heating unit, andin this embodiment comprises a metallic shallow cone-shaped wall 82having a central, generally flat portion 33 which is formed with acentral aperture defined by an upstanding annular lip 36. Projections85, corresponding in position and number to the recesses or notches 39,are struck-out from the flat portion 83, and are constructed to engagewithin respective recesses 3s. The edge margins of the wall 32 arecurved upwardly, as shown at at, and adjacent this edge margin. thereflector may be .formed with a pair of diametriof the resistors 2t and2!, and these r heans may take the form of the binding posts iii and 38,as herein shown, which are respectively connected to the leads 22 and23. The binding posts, it will be appreciated, are electricallyinsulated-from the reflector means 530, as for instance in the mannershown in the drawing.

.Means as is provided for holding the reflector means 3i asembled withthe heating unit. The holding means 89 extends from the heating unit,through the opening 25 and isv constructed and arranged to press thereflector against the heating unit. the particular embodiment of theinvention, the holding means- 89 comprises an upper headed portionformed by a generally inverted cup-shaped member till, the end wall ofwhich is curved to facilitate connection thereto of a screw-threadedstud 6i, and comprises also an outer inverted cup-shaped member 6?,arranged to receive the member 6E3 substantially in nesting relation.The members it and 62 are held together in any suitable manner,preferably by a force fit. The outer member d2 may be of anfornamentalnature, and may carry indicia, such as that suggested at 63, on its endwall. The flange wall of the outer member 62 is of a greater extent thanthe flange wall of the member 40, so that the terminating margin of theflange wall of the member d2 bears against the shoulder 2?. length thatit passes through the opening 25, gird through the aperture in thereflector means A lower headed portion, for pressing the refiector meansagainst the heating unit, comprises a cup-shaped? member 84, having itsclosure wall dished inwardly, as shown at 25, to form a recess forreceiving a washer 46 and nut 41. The end wall or the member, isapertured The screw stud M is of such bit to pass the stud thand theflange wall of the member dd is of such diameter that its terminatingmargin bears against the adjacent surface of flat portion 32-3 of thereflector means 3i. When the nut i? is drawn up, the member 44 causesthe reflector means to bear against the terminating margin ofthe flangemeans 24. Thus, the projections 35 are held in the recesses or notches30 and prevent relative rotation of the reflector means with respect tothe heating unit about the holding means.

The parts of the heating means hereinbefore described may be assembledin any desirable manner. By way of example, the binding posts 3'! and 38may first be properly assembled on the reflector means ti, and then theconductor leads 22 and 23 may be secured to respective binding posts. Asbest seen in Figure 1, the up! per end of each binding post isbifurcated, as

shown at 13, and the respective conductor lead is placed between thefurcations, and the tunations are then squeezed tightly about theconductor lead. If desired, the conductor leads additionally may besoldered to their respective binding posts.

The reflector means 39 may then be positioned with respect to theheating unit, in such manner that the flat central portion 33 bearsagainst the terminating margin of the flange means 26, and theprojections 35 are positioned within respective recesses or notches 3d.The assembled cup-shaped members 438 and d2, carrying the screw stud 65may then be disposed so that the terminal margin of the flange of themember 12 bears against the ,shoulder 2i and the stud M extends throughthe opening 25 and the aperture in the reflector means 3i. As clearlyseen in Figure l, the outer member G2 is so constructed that its flangefits within the enlargement 25 of the opening 25, and its top wall doesnot extend beyond the plane of the upper flat surface of the heatingunit iii.

The cup-shaped member 54% may then be placed in position on the studiii, and the washer tit and nut d? assembled with the stud hi, the nutbeing drawn up sufic'iently so that the member 36 presses the flatcentral portion 33 of the reflector means 3i against the terminatingmargin of the flange means 25. It will be clear that the interfittingrecesses 3d and projections 35 prevent relative shifting of thereflector means and the heating unit during and after assembly thereof,and therefore certain parts, like the conductor leads, binding posts,and insulating material, are not subjected to strains which might be setup if relative shifting were not prevented; Also, the recesses 30 andprojections 35 provide for a predetermined assembly of the heating unitand reflector means.

As shown in this embodiment, referring particularly to Figure 2, two ofthe binding posts 8? and 38 are connected together by a jumper strap 39,the binding post 38 of this connection also having attached thereto aconductor strap ductor straps 53 and 54 respectively connected thereto,these straps also leading to the termi- I nal block 5!. and havingscrew-connections 55 and 56 respectively, for receiving and holdingconductors leading from a source of energy- A ground conductor, such asthe conductor strap 51, may be connected to the reflector means, thisstrap having a connection screw for receiving and holding a conductorleading to a suitable ground.

It will be appreciated that the terminals 52, 55, and 56 may beconnected in electrical circuit in such manner that one, or the other,or both, of the resistors and 2| may be selectively energized. Theparticular construction of the heating unit makes it non-susceptible towarping, apparently because of the provision of the centrally disposedflange means 24, or the peripheral flange means l3, or the-combinationof the two. i

From the foregoing it will be apparent to'those skilled in the art thatI have accomplished at least the principal object of my invention, andit also will be apparent to those skilled in the art that the embodimentherein described may be spaced from said opposite side, and having aportion bearing against said plate means; a plurality of connectionposts-carried by but insulated from said reflector means, said postsbeing electrically connected to respective connection leads;

plurality of connection leads; reflector meansv holding means,constructed and arranged to press said reflector means portion, againstsaid plate means; and means, in part carried by said plate means and inpart carried by said reflector means, constructed and arranged toprevent relative shifting of said reflector means and said plate meansabout said holding means.

2. Heating means, comprising: a cast-metal plate, having opposite sides,one side providing a heating surface, and the opposite side beingprovided with channel means, and'having central laterally extendingflange means; granular refractory insulating material retained withinsaid channel means; electric resistor means, em-

bedded in said insulating material, in such manner that said resistor isheld spaced from those surfaces defining saidchannel means, saidresistor means having a plurality of connection leads extendingoutwardly from said material; reflector means, positioned adjacent tosaid opposite side, and having a central apertured portion bearingagainst the terminating surface of said flange means, said-reflectormeans having also a plurality of binding posts to which said connectionleads are respectively electrically connected; holding means, comprisinga screw stud extending from said plate and through said reflector meansaperture, and nut means threaded on said stud and pressing saidreflector means portion against the terminating surface of said flangemeans; said flange means being formed with a plurality of recesses andsaid reflector being formed with corresponding projections and arrangedas to prevent relative rotation of said reflector means and said plateabout-said stud.

3. Heating means, comprising: a support, having opposite sides, andhaving a tubular flange extending laterally from one of said sides;reflector means, spaced from said one side,

and having a portion bearing against the terminating margin of saidtubular flange; holding means extending from said support through saidtubular flange and to said reflector means, con-- structed and, arrangedto press said reflector means portion against said terminating-margin;and means, in part carried by said reflector means and in part carriedby said tubular flange,

constructed and arranged to prevent relative shifting of said reflectormeans and said support about said holding means.

4. Heating means, comprising: a heating unit, having opposite sides, andhaving also an aperture extending therethrough, said aperture having anenlarged portion entering from one side and forming a shoulder with theremaining portion of said aperture; reflector means, positioned adjacentthe opposite side of said heating unit, and having a portion bearingagainst said heating unit, said portion being apertured; and holdingmeans, comprising inverted cup-shaped means disposed within the enlargedportion of said heats ing unit aperture and having its terminatingmargin bearing against said shoulder, saidinverted cup-shaped meanshaving a screw-threaded stud extending through the apertures in saidheating unit and in said reflector means, and said holding meanscomprising also cup-shaped means having an aperture passing said stud,and nut means threaded on said stud and pressing the terminating marginof said cup-shaped means against said reflector means portion.

5. Heating means, comprising: a support, carrying heat producing means;reflector means, positioned adjacent to said support, and having aportion bearing against said support; holding means, holding saidreflector means in assembled relation with said support; and means,comprising interfltting projection means and recess means, in partcarried by said support and in part carried by said reflector means,constructed and arranged to prevent relative shifting of said reflectormeans and said support about said holding means.

6. Heating'means, comprising: a support, having flange means extendingfrom a surface thereof, said flange means having recess means in itsmeans portion.

7. Heating means, comprising: a heating unit, having opposite sides, andhaving also an aperture extending therethrough, said aperture havinganenlarged portion entering from one side and forming a shoulder with theremaining portion of said aperture, and said heating unit having atubular flange adjacent said aperture and extending from the oppositeside, said flange having recess means in its terminating margin; re-

1 flector means, positioned adjacent said opposite side of said heatingunit, and having a portion bearing against the terminating margin'ofsaid fitting in respective recesses and so constructed 7! tubularflange, said portion being apertured, and

having projection means fitting into said recess means; and holdingmeans, comprising inverted cup-shaped means disposed within the enlargedportion ofsaid heating, unit aperture and having its terminating marginbearing against said shoulder, said inverted cup-shaped, means having ascrew-threaded stud extending through the apertures in said heating unitand in said refiector, and said holding means comprising also cup-shapedmeans having an aperture passing said stud, and nut means threaded onsaid stud and pressing the terminating margin of-said cupshaped meansagainst said'refiector means portion.

8. Heating means, comprising: a support; electrical insulating materialcarried by said support; electrical resistance means, carried by saidinsulating material, and having extending terminal means; reflectormeans, having connection means to which said terminal means areconnected; holding means, constructed and arranged to hold saidreflector means assembled with said support; and means, separate fromsaid terminal means,

constructed and arranged to prevent relative shifting of said reflectormeans and said support about said holding means; so that said terminalmeans are relieved of the strain of opposing such relative shifting.

9. Heating means, comprising: a support, having recess means in asurface thereof; granular refractory insulating material disposed withinsaid recess means; electrical resistance means embedded within saidinsulating material, and having terminal means extending from saidinsulating material; reflector means, having 'connection means to whichsaid terminal means are connected; holding means, constructed andarranged to hold said reflector means assembled with said support; andmeans, separate from said terminal means constructed and arranged toprevent relative shifting of said reflector means and said support aboutsaid holding means, so that said terminal means are relieved of thestrain of opposing such relative shifting.

ERNEST N. CALHOUNL

